Migrate is horribly broken! Migrate works awesome! Both are true. (Yes!) So Keith Dechant reported migrating a live Drupal 7 site to Drupal 8. Melissa Anderson is migrating a Drupal 6 site and gets mostly bugs. How is this possible? Well, Keith was coding his way around bugs, not just using what core provided (this should be obvious since we do not yet provide Drupal 7 sources in core) and Melissa had a site builder approach to it. Both of them are poised to contribute: Keith will share his code for Drupal 7 in the sandbox and Melissa files great bug reports and writes documentation with tips of how to use xdebug to find out what's broken with a migration. At this juncture if you are not prepared for either you will have a bad time with using migrate. Otherwise, see, it works!